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【期刊论文】Sol-gel-derived c-axis oriented ZnO thin films
包定华, Dinghua Bao a, b, ), Haoshuang Gu b, Anxiang Kuang b
Thin Solid Films 312 1998. 37-39,-0001,():
-1年11月30日
c-Axis oriented zinc oxide thin films were prepared by sol-gel process on fused quartz substrates. The structure, optical and electrical properties of ZnO films were investigated. Growth of the thin films strongly depends on heat-treatment conditions. The c-axis lattice constants of the thin films and the band gap are a little bigger than that of ZnO crystal. The differences between the thin film and crystal might be attributable to the grain boundaries and imperfections in thin films.
ZnO thin film, Sol-gel, Optical and electrical properties
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包定华, Dinghua Bao*, Xiaoqing Wu, Liangying Zhang, Xi Yao
,-0001,():
-1年11月30日
Calcium modified lead titanate sol was synthesized using lead acetate trihydrate, calcium nitrate tetrahydrate and titanium tetra-n-butoxide as starting materials, methanol and ethanolamine were elected as solvent and stabilizing or complexing agent, respectively. (Pb0.76Ca0.24)-TiO3 thin films were prepared on platinum-coated silicon and fused silica substrates with the solution using the pinning method. The surface morphology and crystal structure, surface compositions and chemical tates, electrical and optical properties of the thin films were investigated. The films have good composition homogeneity and thickness uniformity. The dielectric constant and dissipation factor of 1 kHz at room temperature were found to be 280 and 0.027, respectively, for thin films with 0.5mm hickness annealed at 6008C for 1 h. The remanent polarization and coervive field were 15 mC/cm2 and 64 kV/cm, respectively. The thin
(, Pb,, Ca), TiO3 thin films, Structure, Electrical and optical properties, Sol-gel technique
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【期刊论文】Band-gap energies of sol-gel-derived SrTiO3 thin films
包定华, Dinghua Bao a) Xi Yao Naoki Wakiya, Kazuo Shinozaki, and Nobuyasu Mizutani
,-0001,():
-1年11月30日
Band-gap energies of sol-gel-derived SrTiO3 thin films were studied in terms of annealing temperature and film thickness. The band-gap energies of highly crystallized films were comparable to those of single crystals reported, whereas for poor-crystallized films, their band-gap energy values were much larger than those of single crystals. The larger band-gap energy shift was believed to be mainly due to both quantum size effect and existence of amorphous phase in thin films. The band-gap energies also showed a strong dependence on film thickness. There was a critical film thickness (~200 nm), above which the films had band-gap energies close to those of crystals or bulks, but below that, the values shifted largely, which can be attributed to the influence of crystallinity of thin films. Such a thickness effect of band-gap energy should be of high interest in optical device applications.
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【期刊论文】Growth, structure, and properties of all-epitaxial ferroelectric (Bi,La)
包定华, Dinghua Bao, a) Sung Kyun Lee, Xinhua Zhu, Marin Alexe, and Dietrich Hesse
APPLIED PHYSICS LETTERS 86, 082906 (2005),-0001,():
-1年11月30日
All-epitaxial (Bi,La) 4Ti3O12 (BLT) /Pb(Zr,Ti) O3(PZT)/(Bi,La) 4Ti3O12 trilayered ferroelectric thin films were prepared on SrRuO3 sSROd-covered SrTiO3s011d substrates by pulsed-laser deposition. Epitaxial relationships were identified to be BLT (118) iPZT (011) iSrTiO3(011), and BLTf1(1)0g iPZTf100g iSrTiO3f100g. Atomic force microscopy observation of the surface showed that the upper BLT layer is composed of rod-like grains. Cross-sectional transmission electron microscopy investigations revealed ferroelectric 90
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